If you'll disconnect computer then for sure you'll have to go to the dealer.
Here is your codes:
DTC B1552 Keep Alive Memory (KAM) Error
Circuit Description
DTC B1552 indicates that the KAM in the instrument cluster is reset. The KAM in the instrument cluster normally resets whenever power or ground removes from the instrument cluster. DTC B1552 sets when the battery is disconnected and reconnected, for example.
Conditions for Setting the DTC
The DTC sets under the following conditions:
If the Class 2 serial data line is shorted and the PZM attempts to activate the low power mode (approximately 20 minutes after the ignition switch is turned to OFF).
Power or ground is disconnected from the instrument cluster.
Power or ground is reconnected to the instrument cluster.
Action Taken When the DTC Sets
When the DTC sets, the following actions occur:
The instrument cluster KAM data (trip odometer) is reset to an initial value and the Average Fuel Economy.
Fuel Used display values are reset to zero.
Diagnostic Aids
If DTC B1552 ses without a battery disconnect:
Check for PZM DTC's B1972 or B1973, if current perform the appropriate DTC diagnosis.
Ensure the good terminal contacts exist at IPC connector C1 terminals A1, B1, A12 and B12. If terminal contact is ok , replace the instrumant cluster.
DTC P0603 Control Module Long Term Memory Reset
Circuit Description
The PCM has a memory area where it stores certain data it needs to save when the key is turned OFF. This area is called Keep Alive Memory. This diagnostic test monitors the PCM's keep alive memory for a loss or unintended change of data. If such a condition occurs, DTC P0603 will set.
Conditions for Running the DTC
Tested continuously.
Conditions for Setting the DTC
Keep alive memory checksum does not match previous checksum.
Action Taken When the DTC Sets
Clear all keep alive memory locations.
The Malfunction Indicator Lamp (MIL) will not illuminate.
No message will be displayed.
Conditions for Clearing the DTC
A History DTC will clear after forty consecutive warm-up cycles with no failures of any non-emission related diagnostic test.
A Last Test Failed (current) DTC will clear when the diagnostic runs and does not fail.
Use a scan tool to clear DTCs.
Interrupting PCM battery voltage may or may not clear DTCs. This practice is not recommended. Refer to Clearing Diagnostic Trouble Codes in PCM Description and Operation.
Diagnostic Aids
If the battery has been disconnected for any reason DTC P0603 will set. The PCM keeps a running check on the memory; if memory changes it resets. An intermittent loss of power or ground to the PCM will cause a reset.